An issue arose on our server the other day where a single commit from an intern caused resources to become constrained and eventually exhausted. This was a result from git command processes exhausting the CPU and tickets were getting queued and eventually dropped.
We have the add-on https://marketplace.atlassian.com/plugins/org.christiangalsterer.stash-filehooks-plugin/server/overview that does this on a per-repository basis. However at our current scale there is no way to enforce this kind of thing globally. Similarly in the way Github does https://help.github.com/articles/working-with-large-files/ We have git-lfs enabled and would rather large files be stored via git-lfs instead. So we want to allow large files in git just in the right way.